On the Prevention page, I showed how many common preventive medical interventions don’t save money, even if pretty much everyone agrees that the interventions extend lives and improve health. To explain this concept, first an analogy:

THE TALE OF TWO SEEDS

It is true people whose cancers are detected at a small size are more likely to be cured than those whose cancers are detected at a larger size. Many people then conclude early detection is extremely important to prevent deaths from cancer. Unfortunately, reality is not so simple.

To illustrate this point, imagine you have prize rose bushes and two birds drop two different seeds at the base of two different rose bushes at the same time. One seed is a fast-growing vine, the other a slow-growing shrub like a holly. If left alone, both invading plants will take over and overwhelm the rose bushes. The vine will ultimately kill the rose bush by enveloping it. The holly will kill the rose bush by growing larger than the rose bush and covering it up. Each can damage or kill the rose bush if not removed before it reaches a critical size.

Now imagine you were away from your garden for many weeks. While you were gone, both seeds germinated at about the same time and started growing. When you return home, you go outside to inspect your prize flowers and you see the vine growing halfway into one of the rose bushes. The holly by another rose bush is less than a foot tall.

The vine is impossible to remove without damaging the rose bush, because it grew so fast and is so intertwined in the branches. The holly is much easier to remove. It barely reaches the lower branches. The damage caused by the invading plants was caused by the speed and nature of their growth, not when they were detected.

The same reality exists in cancer detection. People assume the small cancer is more curable because it was caught early. A more accurate understanding is a less aggressive cancer not only grows slower, but is less likely to invade the surrounding normal tissue or break apart and spread all over the body (metastasize). The small cancer’s slow growth and lack of aggressiveness is the reason it’s detected at an earlier size and simultaneously allows the treatment to be more successful. The timing of cancer detection has little to do with it.

LUNG CANCER

There is actually proof early detection of lung cancer doesn’t save lives. Several clinical trials performed in the 1960s tested different strategies to prevent lung cancer deaths in heavy smokers. The researchers checked chest x-rays and looked for cancer cells in patients’ sputum samples. In those patients whom lung cancer was detected, the lumps in their chest were smaller. However, the people whose cancer was detected early died at the same rate as the people left alone. Early results of lung CAT scan screening in heavy smokers find the same thing.

THE GIMeC INFLUENCE

To make one more point that the value of prevention is overstated, let’s look at other cancers. There are only three cancers for which nearly all doctors agree that early detection saves lives: breast, cervical, and colon. For other cancers, there is a range of speculation about how effective early detection might be, though clearly GIMeC has convinced the American people early detection is crucial for all cancer care.

A recent national study found 87% of adults believe routine cancer screening is almost always a good idea and 74% say finding cancer early saves lives.⁴ Two-thirds said they would want to be tested for cancer, even if nothing could be done. 56% said they would want to be tested for pseudo-disease: cancers growing so slowly they would never cause problems during the person’s lifetime even if untreated. Clearly, the GIMeC assumptions have penetrated the American psyche.